The California Department of Public Health (CDPH) is advising consumers not to eat recreationally harvested mussels, clams or whole scallops from Marin County. Dangerous levels of paralytic shellfish poisoning (PSP) toxins have been detected in mussels from this region; clams and scallops may also pose a health risk. The naturally occurring PSP toxins can cause illness or death in humans.

This warning is in addition to the annual mussel quarantine that was extended on October 31, 2012, for Del Norte and Humboldt counties. That quarantine remains in effect.

This warning does not apply to commercially sold clams, mussels, scallops or oysters from approved sources. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing.

PSP toxins affect the central nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating toxic shellfish. These symptoms are typically followed by loss of balance, lack of muscular coordination, slurred speech and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur. Cooking does not destroy the toxin.